Lossless Audio Playback on Samsung BD-C6900

[zamarac17]

So far I wasn't lucky to convert multichannel Flac to multichannel LPCM. I tried:

eac3to input.flac output.lpcm

which results in LPCM file that plays on PC very slowly. VideoHelp thread says, it has non-standard header content.

However, according to Samsung BD-C6900 spec, it can decode DTS-DH and Dolby True HD - hopefully via LAN too, not only from a BD disk. So, how to edit Samsung BDP profile to add conversion of 5.1 Flac to 5.1 DTS-HD or Dolby True HD, if at all possible (probably not with ffmpeg)?

I found similar threads on ffmpeg conversion, so may be I should transcode Flac to LPCM or Dolby TrueHD saved in MP4 or MKV container instead of raw LPCM for normal multichannel audio playback via LAN? This way the device might comply with artificially restrictive DLNA spec, while at the same time play lossless within an officially supported container.

Another thing, Samsung doesn't play .lpcm and .raw extensions, but does .l16 one, which plays slowly via Asset UpNP Server. I wonder if it interprets .l16 format always meaning 2-channel lpcm? So what would be the right extension for 6-channel lpcm? Mezzmo filters all these extensions - so I had to add lpcm and l16 extensions to filters, the file shows up in Mezzmo PC Console, but not on TV screen - why?

[zamarac17]

Here is fresh citation from FFMpeg mailing list:

"What's the right command to transcode 5.1 Flac to 5.1 LPCM audio in ffmpeg?

FFmpeg does not support encoding Bluray PCM, patch welcome."

So, since Mezzmo uses FFMpeg for transcoding, it sounds impossible regardless of the device profile mod, the resulting file is garble LPCM at best.

[Paul]

OK - let's forget about attempting to encode to multichannel LPCM. How about we add support into your device profile for multichannel .DTS files? The Samsung BDP specification states it supports decoding DTS audio. Contact us at support [at] conceiva [dot] com for the new device profile.

[zamarac17]

Rergarding LPCM transcoding, I tried eac3to instead of ffmpeg, and when multichannel Flac is transcoded by eac3to to LPCM, it works OK on PC. I verified the transcoded file by importing it to Audacity, and it plays the same number of channels as original Flac with original quality. The problem still is, when DLNA interface is used, only 2-channel LPCM file with extension .l16 plays correctly via LAN on the BD player, since .l16 seems to be locked to 44100/16/2 by default. Any other LPCM media format with .l16 extension will be garbled, and any extension for LPCM file other than .l16 ignored by Samsung, if DLNA is used. So, it looks like the player just checks the file extension, since LPCM format is missing any header by default.

Yes, I'd like to try Flac-to-DTS transcoding - pls email me the profile to the same address. Hopefully it will play nicely via 7.1 RCA on my player. However, its not lossless format, and with the same success I can transcode Flac to lossy AC3 or AAC - right? DTS HD Master or Dolby TrueHD is a different story, but again DLNA will be the road block I presume? Can you do something around DLNA restrictions?

[Paul]

With regards the multi-channel LPCM file that you created, I'd like to confirm that your Samsugn BDP can play it or not via DLNA streaming. Please try this: Rename the file extension of your LPCM file to ".wav" and add it into your Mezzmo library. In Mezzmo, click on the .wav file and check the Properties pane to see if the audio characteristics look right (e.g. number of channels, etc.). Then, go to the Media Device dialog and edit your Samsung BDP device. In the Device Settings dialog, go to the Transcoding tab and turn off the transcoding checkbox. Restart your Mezzmo server and try streaming the wav file to your Samsung BDP. If it does not play, then please turn on logging and restart your Mezzmo server. Try streaming the file again, and when it fails, stop your Mezzmo server and exit Mezzmo. Zip up all your logs and send them to us at support [at] conceiva [dot] com.

[zamarac17]

Hi Paul,

Multichannel LPCM file transcoded from Flac with eac3to, has no header whatsoever. So, how renaming it to wav can possibly add a header to it, so that Mezzmo would ID its media info? I can transcode it to wav instead of renaming, but unfortunately, Samsung BD players don't support wav playback - meaning, when I rename .l16 to wav, it doesn't show any longer in list of playable files in DLNA interface. I assume, it wouldn't show either in UpNP interface, since WAV is not on the Samsung list (see above link) of supported media formats.

[Paul]

You're right, Zamar. We'll email you a device profile with DTS to test shortly.

[zamarac17]

I wonder if you use any transcoders other than ffmpeg? It might make more sense to transcode 5.1 Flac into 5.1 LPCM or Wav and pack it inside MPG or MKV container. Its quite possible that Samsung's audio format support inside video containers is broader than stand alone audio supported format choice. Is it possible to create such profile?

[Paul]

Is it possible to create such profile?

Yes it is. We'll start with the DTS version as discussed and then continue testing with other variants. Sorry for the delay - we should get the DTS profile to you today for testing.

[zamarac17]

The main problem with playing multichannel audio on streaming capable hardware like BD players is that many are restricted to not support generic UpNP protocol, but rather limited to its LPCM version. So you're stack with a set of predefined by LPCM and further limited by the player maker A/V formats, even in transcoding attempts. Anything else simply wouldn't play via DLNA interface. More flexible way is to augment a streaming server like Mezzmo with an App installable via BD player interface and fully using its API, like Samsung Apps distributed via their Apps Store. So its unfortunate, but I feel the concept of a streaming server alone is too limited to address multichannel lossless audio playback.

Still wonder, if its possible to extend a choice of officially supported by a BD player A/V file formats by an installable App, or it's achievable only by modding the Player's firmware? It looks like in many instances its not limited by decoding & rendering chipsets, because different models are often using the same chipset, but support different A/V format subsets. So its more marketing driven, and by product differentiation policy within a maker's product line.